Various light emitting devices have been proposed in the prior art. A light emitting device includes a light emitting element mounted on a substrate. Japanese Laid-Open Patent Publication No. 2003-092011 describes an example of a light emitting device in the related art. In the light emitting device, a wiring pattern is formed on an insulating layer applied to a metal substrate, and a light emitting element such as a light emitting diode (LED) is mounted on the wiring pattern.
In recent years, applications of the light emitting device are expanding to lighting devices and display devices. With such applications, light emitting elements are desired to be mounted at high density. Therefore, refinement of the wiring layer (pitch-narrowing of the wirings) is required. However, since the wiring layer to which the light emitting elements are to be mounted is formed by a subtractive method and the like, making a pitch of the wiring layer narrow is difficult. Further, in the above light emitting devices, heat is generated in the light emitting diodes accompanying electric conduction thereof. This decreases light emitting efficiency of the light emitting diodes. Thus, the wiring layer tends to be formed thick in order to efficiently release the heat that has been generated by the light emitting diodes from the wiring layer. In such a case, the pitch-narrowing of the wirings further becomes difficult.